The Protective Role of Autophagy in Matrix Metalloproteinase-Mediated Cell Transmigration and Cell Death in High-Glucose-Treated Endothelial Cells

Diabetes mellitus may cause vascular endothelial damage via endothelial matrix metalloproteinase-2 (MMP-2). The role of endothelial autophagy in MMP-2-mediated cell injury in response to high-glucose (HG) stimulation was rarely described. In this study, we used HG-treated human umbilical vein endothelial cells (HUVECs) to investigate the effect of autophagy on MMP-2-induced cell transmigration and apoptosis. THP-1 transmigration was detected by the transmigration assay. Light chain 3 (LC3, representing autophagy), MMP-2, and poly (ADP-ribose) polymerase (PARP, representing apoptosis) of HG (33 mM)-treated HUVECs were evaluated by western blot analysis. The MMP-2 activity was also examined by gelatin zymography. We used GM6001 (10 mu M, an MMP-2 inhibitor) to investigate the relationship of MMP-2 and THP-1 transmigration. Using 3-methyladenine (3MA, 5 mM, an LC3 inhibitor), we explored the effects of autophagy on MMP-2 expression, THP-1 transmigration, and apoptosis. Our results showed that HG increased LC3-II expression, MMP-2 activity, THP-1 transmigration, and cleaved PARP expression in a time-dependent manner (0-48 h); among them, LC3-II appeared earlier (0-24 h) than the others (24-48 h). GM6001 suppressed MMP-2 activity and ameliorated THP-1 transmigration. 3MA suppressed LC3-II expression and increased MMP-2 expression, THP-1 transmigration, and cleaved PARP expression. From these sequential findings, we demonstrated that autophagy plays a protective role in MMP-2-mediated cell transmigration and cell death in HG-stimulated HUVECs.